Silicon Wafer Polishing Composition for Micro-Defect Reduction

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Solution Overview

Problem

Existing polishing compositions for semiconductor wafers fail to adequately reduce micro-defects, particularly in the finish-polishing stage, due to insufficient surface quality control.

Innovation Solution

A polishing composition comprising an abrasive, a basic compound, a wetting agent, and a non-ionic surfactant, with specific surface tension and dilution ratio adjustments to balance protective effects and conformability, reducing micro-defects by optimizing surface tension (Yud) to 64 mN/m or less and dilution ratio (Yd/Yud) to 1.10-1.40.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional polishing compositions are used, then polishing can be performed, but micro-defects cannot be sufficiently reduced

Engineering Contradiction:

Improvesurface qualityVSAvoidmicro-defects

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by optimizing the surface tension of the polishing composition to 64 mN/m or less and controlling the dilution ratio (Yd/Yud) to 1.10-1.40. These specific parameter adjustments enhance the protective effects on the abrasive and wafer surface while improving conformability in water, directly reducing micro-defects and achieving superior surface quality after polishing.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If surface tension is reduced to improve conformability, then protection and conformability improve, but excessive reduction may compromise stability

Engineering Contradiction:

Improveprotective effectVSAvoidcomposition stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent carefully adjusts the surface tension parameter to 64 mN/m or less while controlling the dilution ratio (Yd/Yud) to 1.10-1.40. This optimized parameter range achieves the right balance between protective effect and conformability without compromising composition stability, ensuring reliable performance during polishing.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The optimized polishing composition effectively reduces micro-defects on semiconductor wafers by enhancing abrasive and wafer surface protection, improving polishing stability, and facilitating easy removal of foreign substances, thereby achieving superior surface precision.

Implementation Method 1

a surface tension Yud is not higher than 64 mN/m

Methodology Applied

Scientific EffectSurface tension reduction: Surface Tension

Implementation Method 2

a non-ionic surfactant

Methodology Applied

Scientific EffectSurfactant action: Surfactant

Implementation Method 3

a water-soluble polymer such as hydroxyethyl cellulose... works to hydrophilize the surface of the semiconductor wafer

Methodology Applied

Scientific EffectHydrophilization: Hydrophile

Implementation Method 4

an abrasive

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS12435244B2Polishing composition and method of polishing silicon wafer

Publication Date: 2025.10.07 NITTA DUPONT INC

AI summary

A polishing composition is provided that can reduce micro-defects on a semiconductor wafer after polishing. A polishing composition includes: an abrasive; a basic compound; a wetting agent; and a non-ionic surfactant, where the surface tension Yud is not higher than 64 mN/m, and the ratio of the surface tension after dilution with water by a factor of 20, Yd, to the surface tension Yud, denoted by Yd/Yud, is not lower than 1.10 and not higher than 1.40. Here, the surface tensions Yud and Yd are measurements at 25° C.